What you can do right now to extend battery life

If your iPhone battery drains faster than it used to, the first step is to check what's consuming power and adjust settings—you may not need a replacement at all. Start by going to Settings > Battery > Battery Health & Charging to see the maximum capacity percentage. If it's above 80%, software changes often restore hours of runtime. If it's below 80%, the battery itself is degraded and will need replacement.

Before you replace anything, try these adjustments: turn off background app refresh for apps you don't need constant updates from, lower screen brightness or enable Auto-Brightness, switch to Low Power Mode (Settings > Battery), and disable location services for apps that don't need it. Close apps running in the background by swiping up from the bottom of the screen. These steps cost nothing and often buy you months of usable battery life.

If your phone is overheating or the battery percentage jumps randomly, a software glitch may be the culprit. Restart your iPhone by holding the power button and volume button together, then sliding to power off. Wait 30 seconds and turn it back on. If the problem persists after a restart, the battery itself is likely failing.

Key Takeaways

  • Check your maximum battery capacity in Settings > Battery > Battery Health & Charging; anything below 80% means the battery is degraded and should be replaced.
  • Disabling background app refresh, lowering screen brightness, and using Low Power Mode can extend battery life without any hardware change.
  • Apple and authorized repair shops charge between $50 and $100 for battery replacement depending on your iPhone model, and the process takes one to two hours.
  • Third-party repair shops often cost less but may void your warranty and use non-Apple batteries that degrade faster.
  • If your iPhone is still under warranty or you have AppleCare+, battery replacement is covered if capacity has dropped below 80%.

When to replace the battery yourself versus getting professional help

Replacing an iPhone battery yourself is possible but requires opening the phone, which voids the warranty and risks damaging the screen, logic board, or water seals. Apple's newer models (iPhone X and later) use adhesive to hold the battery in place, making removal harder without the right tools. If you're comfortable with electronics repair and have watched detailed guides for your specific model, third-party kits cost $20 to $40 and include the battery, adhesive strips, and tools.

Professional replacement is safer and faster. Apple Stores charge $69 for iPhone 15 and $79 for older models, though prices vary slightly by region. The repair takes one to two hours, and Apple guarantees the work. Authorized Apple Service Providers (found at apple.com/repair) charge the same rates and offer the same warranty. Independent repair shops often charge $40 to $60 but may use aftermarket batteries that don't last as long as genuine Apple parts.

If your iPhone is under warranty or you have AppleCare+, battery replacement is covered at no cost if the maximum capacity has dropped below 80%. Check your coverage at apple.com/support by entering your serial number. If you're out of warranty, paying for professional replacement protects your phone's water resistance and ensures the new battery meets Apple's specifications.

How to back up your data before battery service

Before taking your iPhone in for battery replacement, back up your data so you don't lose photos, messages, or settings if something goes wrong during the repair. The fastest method is iCloud: go to Settings > [Your Name] > iCloud > iCloud Backup, tap Back Up Now, and wait for the progress bar to finish. This uploads your entire phone to Apple's servers and takes 10 to 30 minutes depending on how much data you have and your internet speed.

If you prefer to keep a local copy on your computer, connect your iPhone to a Mac or Windows PC, open Finder (Mac) or iTunes (Windows), select your phone, and click Back Up Now. This creates an encrypted file on your computer that includes everything on your phone. Either method works; iCloud is easier if you don't have a computer nearby, and a local backup is faster if you have a lot of data.

Signs your battery needs replacement versus other problems

A failing battery shows specific patterns: the phone shuts down at 20% or 30% charge even though the percentage display is accurate, the battery percentage jumps from 50% to 0% without warning, or the phone is warm to the touch during normal use. These point to a degraded battery. Check Settings > Battery > Battery Health & Charging again—if maximum capacity is below 80%, replacement will fix the problem.

Other issues can look like battery problems but aren't. If your phone only drains fast when using specific apps (like games or video), those apps are the culprit, not the battery—uninstall or update them. If the phone drains fast only when it's cold, that's normal; lithium batteries lose capacity temporarily in cold weather and recover when warmed up. If the battery drains fast only after a recent iOS update, restart your phone and give it 24 hours; iOS updates sometimes cause temporary high power use while indexing files.

What happens during a professional battery replacement

When you take your iPhone to Apple or an authorized repair shop, the technician will first verify the battery capacity using Apple's diagnostic tools, then power off your phone and remove the display (which requires heating and careful prying). The old battery is disconnected and removed—newer iPhones use adhesive, so this step takes the longest. The new battery is installed, the display is reattached and sealed with new adhesive, and the phone is powered on to confirm it works.

The entire process takes one to two hours. You'll be without your phone during this time, though some Apple Stores offer loaner devices. After replacement, your phone should hold a charge for a full day of normal use again. The new battery comes with a one-year warranty, so if it fails prematurely, the repair shop will replace it again at no cost.

Aftermarket batteries and third-party repair shops

Independent repair shops and online retailers sell replacement batteries for $20 to $40, which is cheaper than Apple's $69 to $79 service fee. These batteries are usually genuine Apple parts salvaged from other phones, or new batteries made by third-party manufacturers like Anker or iFixit. Genuine salvaged batteries perform identically to new ones. Third-party batteries are safe but often degrade faster—they may reach 80% capacity after 300 to 400 charge cycles instead of 500 to 600.

Using a third-party repair shop voids Apple's warranty on battery issues, though your phone's other components remain covered if you didn't damage them during the repair. If you choose this route, ask the shop whether they use genuine or aftermarket batteries and whether they offer a warranty on the replacement. Some shops may provide their work for six months; others offer no warranty at all.

Preventing battery degradation in the future

iPhone batteries degrade with every charge cycle—a full cycle is draining the battery from 100% to 0% and back to 100%. You can't stop degradation, but you can slow it. Keep your phone between 20% and 80% charge as much as possible; charging to 100% and letting it drop to 0% stresses the battery. Enable Optimized Battery Charging in Settings > Battery > Battery Health & Charging—this limits charging to 80% overnight and only charges to 100% when you need it.

Avoid heat: don't leave your phone in direct sunlight, in a hot car, or under a pillow while charging. Heat accelerates degradation more than anything else. Use the original Apple charger or a certified third-party charger; cheap chargers can overheat the battery. If your phone gets hot during normal use, close background apps and lower screen brightness until it cools down.

Frequently Asked Questions

How long does an iPhone battery last before it needs replacement?

Apple designs batteries to retain 80% capacity after 500 full charge cycles. In real use, this typically means two to three years before the battery noticeably degrades. If you charge your phone once a day, you'll hit 500 cycles in about 18 months. Heavy users who charge twice a day may need replacement sooner.

Can I use my iPhone while it's charging?

Yes, but it generates heat, which degrades the battery faster. If you need to use your phone while charging, use a lower-power charger (5W instead of 20W) to reduce heat. Avoid gaming or video streaming while plugged in, as these activities generate the most heat.

Does Low Power Mode damage the battery?

No. Low Power Mode reduces processor speed and background activity to extend runtime, but it doesn't harm the battery. You can use it whenever you want without side effects. It's a safe way to stretch battery life between charges.

What's the difference between battery health and battery capacity?

Battery capacity is the total amount of charge the battery can hold right now, shown as a percentage of its original capacity. Battery health is a broader measure that includes capacity plus the battery's ability to deliver power under load. A battery at 85% capacity is still in good health; one at 70% is degraded and should be replaced.

Will replacing the battery fix my phone if it's slow?

Only if the slowness is caused by battery degradation. iPhones throttle processor speed when the battery can't deliver enough power, which makes the phone feel slow. If your battery capacity is below 80%, replacement will restore speed. If capacity is above 80%, slowness is caused by something else—try restarting your phone or updating iOS.